A fuel injection valve of the cylinder injection type that supplies fuel directly into a combustion chamber of an internal combustion engine is per se known (refer to Patent Document #1). When such a fuel injection valve is attached to its cylinder, an annular seal member is sandwiched between the inner circumferential surface of the fuel injection valve fitting hole and the outer circumferential surface of the nozzle that is inserted into the fuel injection valve fitting hole, and thereby leakage of combustion gases is prevented.